Sick infants admitted to the neonatal intensive care unit (NICU) are subjected to an average of 14 painful procedures per day. These procedures are known to alter behavior, pain sensitivity, immune function and hypo-thalamic-pituitary-adrenocortical reactivity. In addition, these procedures are documented to result in bradycardia, systemic hypotension and arterial oxygen desaturation or "hypoxemia". However, it is unclear whether procedure-related hypoxemia results in tissue hypoxia, oxidative stress, and cell injury. This new investigator grant application responds to PA-06-542 "Mechanisms, Models, Measurement, & Management in Pain Research (R21)." Our long-term objective bridges the special interest area of pain in preterm neonates exposed to multiple medical interventions and the priority research topic of elucidating the complexity of biobehavioral pain. It also draws on the PI's 20 years of experience as a clinical nurse/nurse manager/clinical director of the Loma Linda University (LLU) NICU, the largest interdisciplinary neonatal intensive care center in the Western United States, and her doctoral research in hypoxia at the LLU Center for Perinatal Biology. The project goal is to begin exploration of the relationship between procedural pain and hypoxia with the effects of a single common NICU procedure such as non- emergent endotracheal intubation. The scientific approach is a prospective cohort study of pre-term neonates. Our interdisciplinary team will determine whether procedural pain increases the following: biobehavioral markers of pain--Premature Infant Pain Profile (Specific Aim 1), biochemical markers of hypoxia--ATP breakdown products hypoxanthine, xanthine, and uric acid--using high performance liquid chromatography (HPLC) of plasma (Specific Aim 2), and biochemical markers of oxidative stress/cell injury--xanthine oxidase activity, plasma 8-nitroxanthine and plasma malondialdehyde levels--using gas chromatography/mass spectroscopy (Specific Aim 3). Lastly, we will determine whether there is a positive correlation between the biobehavioral markers of procedural pain and the biochemical markers of hypoxia and oxidative stress/cell injury (Specific Aim 4). In conclusion, our interdisciplinary team has the expertise to apply our findings to our working model and to the development of better methods for the prevention of long-term morbidity associated with neonatal pain and hypoxia. Sick infants admitted to the neonatal intensive care unit (NICU) are subjected to an average of 14 painful procedures per day. These procedures are known to alter behavior, pain sensitivity, immune function and hypo-thalamic-pituitary-adrenocortical reactivity. In addition, these procedures are documented to result in bradycardia, systemic hypotension and arterial oxygen desaturation or "hypoxemia". However, it is unclear whether procedure-related hypoxemia results in tissue hypoxia, oxidative stress, and cell injury. This new investigator grant application responds to PA-06-542 "Mechanisms, Models, Measurement, & Management in Pain Research (R21)." Our long-term objective bridges the special interest area of pain in preterm neonates exposed to multiple medical interventions and the priority research topic of elucidating the complexity of biobehavioral pain. It also draws on the PI's 20 years of experience as a clinical nurse/nurse manager/clinical director of the Loma Linda University (LLU) NICU, the largest interdisciplinary neonatal intensive care center in the Western United States, and her doctoral research in hypoxia at the LLU Center for Perinatal Biology. The project goal is to begin exploration of the relationship between procedural pain and hypoxia with the effects of a single common NICU procedure such as non- emergent endotracheal intubation. The scientific approach is a prospective cohort study of pre-term neonates. Our interdisciplinary team will determine whether procedural pain increases the following: biobehavioral markers of pain--Premature Infant Pain Profile (Specific Aim 1), biochemical markers of hypoxia--ATP breakdown products hypoxanthine, xanthine, and uric acid--using high performance liquid chromatography (HPLC) of plasma (Specific Aim 2), and biochemical markers of oxidative stress/cell injury--xanthine oxidase activity, plasma 8-nitroxanthine and plasma malondialdehyde levels--using gas chromatography/mass spectroscopy (Specific Aim 3). Lastly, we will determine whether there is a positive correlation between the biobehavioral markers of procedural pain and the biochemical markers of hypoxia and oxidative stress/cell injury (Specific Aim 4). In conclusion, our interdisciplinary team has the expertise to apply our findings to our working model and to the development of better methods for the prevention of long-term morbidity associated with neonatal pain and hypoxia. [unreadable] [unreadable] [unreadable]